Lawrence Summers

The economics commentariat and no small part of the political debate in recent weeks has been consumed with the controversy surrounding the work of my Harvard colleagues (and friends) Carmen Reinhart and Ken Rogoff (RR). Their work had been widely interpreted as establishing that economic growth was likely to stagnate in a country once its government debt-to-GDP ratio exceeded 90 percent. Scholars at the University of Massachusetts have demonstrated and RR have acknowledged that they made a coding error that resulted in their omitting some relevant data in forming their results and also have noted that using updated data for several countries reduces substantially the strength of some of the statistical patterns they asserted. Issues have also arisen with respect to how RR weighted observations in forming the averages on which they base their conclusions.